#ifndef __M_BINDING_H__
#define __M_BINDING_H__
#include "../mqcommon/mq_logger.hpp"
#include "../mqcommon/mq_helper.hpp"
#include "../mqcommon/mq_msg.pb.h"
#include <google/protobuf/map.h>
#include <iostream>
#include <unordered_map>
#include <mutex>
#include <memory>
namespace bitmq
{
    struct Binding
    {
        using ptr = std::shared_ptr<Binding>;
        std::string exchange_name;
        std::string msgqueue_name;
        std::string binding_key;
        Binding()
        {
        }
        Binding(const std::string &ename, const std::string &qname, const std::string &key)
            : exchange_name(ename), msgqueue_name(qname), binding_key(key) {}
    };
    // 队列与绑定信息是一一对应的（因为是给某个交换机去绑定队列，因此一个交换机可能会有多个队列的绑定信息）
    // 因此先定义一个队列名，与绑定信息的映射关系，这个是为了方便通过队列名查找绑定信息
    using MsgQueueBindingMap = std::unordered_map<std::string, Binding::ptr>;
    // 然后定义一个交换机名称与队列绑定信息的映射关系，这个map中包含了所有的绑定信息，并且以交换机为单元进行了区分
    using BindingMap = std::unordered_map<std::string, MsgQueueBindingMap>;
    class BindingMapper
    {
    public:
        BindingMapper(const std::string dbfile)
            : _sql_helper(dbfile)
        {
            std::string path = FileHelper::ParentDirector(dbfile);
            FileHelper::DirectorCreat(path);
            _sql_helper.open();
            createTable();
        }
        void createTable()
        {
            std::stringstream sql;
            sql << "create table if not exists binding_table(";
            sql << "exchange_name varchar(32), ";
            sql << "msgqueue_name varchar(32), ";
            sql << "binding_key varchar(128));";
            _sql_helper.exec(sql.str(), nullptr, nullptr);
        }
        void deleteTable()
        {
            std::string sql = "drop table if exists binding_table;";
            _sql_helper.exec(sql, nullptr, nullptr);
        }
        bool insert(Binding::ptr as)
        {
            std::stringstream sql;
            sql << "insert into binding_table values(";
            sql << "'" << as->exchange_name << "',";
            sql << "'" << as->msgqueue_name << "',";
            sql << "'" << as->binding_key << "'";
            sql << ");";
            _sql_helper.exec(sql.str(), nullptr, nullptr);
            return true;
        }
        void remove(const std::string &ename, const std::string &qname)
        {
            std::stringstream sql;
            sql << "delete from binding_table where ";
            sql << "exchange_name='" << ename << "' and ";
            sql << "msgqueue_name='" << qname << "';";
            _sql_helper.exec(sql.str(), nullptr, nullptr);
        }
        void removeExchangeBindings(const std::string &ename)
        {
            std::stringstream sql;
            sql << "delete from binding_table where ";
            sql << "exchange_name='" << ename << "';";
            _sql_helper.exec(sql.str(), nullptr, nullptr);
        }
        void removeMsgQueueBindings(const std::string &qname)
        {
            std::stringstream sql;
            sql << "delete from binding_table where ";
            sql << "msgqueue_name='" << qname << "';";
            _sql_helper.exec(sql.str(), nullptr, nullptr);
        }
        BindingMap recovery()
        {
            BindingMap result;
            std::string sql = "select exchange_name, msgqueue_name, binding_key from binding_table;";
            _sql_helper.exec(sql, selectCallback, &result);
            return result;
        }

    private:
        static int selectCallback(void *arg, int numcol, char **row, char **fields)
        {
            BindingMap *result = (BindingMap *)arg;
            Binding::ptr as = std::make_shared<Binding>(row[0], row[1], row[2]);
            // 为了防止 交换机相关的绑定信息已经存在，因此不能直接创建队列映射，进行添加，这样会覆盖历史数据
            // 因此得先获取交换机对应的映射对象，往里边添加数据
            // 但是，若这时候没有交换机对应的映射信息，因此这里的获取要使用引用（会保证不存在则自动创建）
            MsgQueueBindingMap &qmap = (*result)[as->exchange_name];
            qmap.insert(std::make_pair(as->msgqueue_name, as));
            return 0;
        }

    private:
        SqliteHelper _sql_helper;
    };
    class BindingManager
    {
    public:
        using ptr = std::shared_ptr<BindingManager>;
        BindingManager(const std::string &dbfile) : _mapper(dbfile)
        {
            _bindings = _mapper.recovery();
        }
        bool bind(const std::string &ename, const std::string &qname, const std::string &key, bool durable)
        {
            std::unique_lock<std::mutex> lock(_mutex);
            auto it = _bindings.find(ename);
            if (it != _bindings.end() && it->second.find(qname) != it->second.end())
            {
                return true;
            }
            Binding::ptr bp = std::make_shared<Binding>(ename, qname, key);
            if(durable)
            {
                bool ret=_mapper.insert(bp);
                 if (ret == false) return false;
            }
            auto &e = _bindings[ename];
            e.insert(std::make_pair(qname, bp));
            return true;
        }
        void unBind(const std::string &ename, const std::string &qname)
        {
             std::unique_lock<std::mutex> lock(_mutex);
            auto it = _bindings.find(ename);
            if (it == _bindings.end() || it->second.find(qname) == it->second.end())
            {
                return;
            }
            _mapper.remove(ename,qname);
            _bindings[ename].erase(qname);
        }
        void removeExchangeBindings(const std::string &ename)
        {
            std::unique_lock<std::mutex> lock(_mutex);
            _mapper.removeExchangeBindings(ename);
            _bindings.erase(ename);
        }
        void removeMsgqueueBindings(const std::string &qname)
        {
            std::unique_lock<std::mutex> lock(_mutex);
            _mapper.removeMsgQueueBindings(qname);
            for(auto& e:_bindings)
            {
                e.second.erase(qname);
            }
        }
        MsgQueueBindingMap getExchangeBindings(const std::string &ename)
        {
            std::unique_lock<std::mutex> lock(_mutex);
             auto it = _bindings.find(ename);
            if (it == _bindings.end())
            {
                return MsgQueueBindingMap();
            }
            return it->second;
        }
        Binding::ptr getBinding(const std::string &ename, const std::string &qname)
        {
            std::unique_lock<std::mutex> lock(_mutex);
             auto it = _bindings.find(ename);
            if (it == _bindings.end())
            {
                return Binding::ptr();
            }
            auto qit = it->second.find(qname);
            if(qit==it->second.end())
            {
                 return Binding::ptr(); 
            }
            return qit->second;
        }
        bool exists(const std::string &ename, const std::string &qname)
        {
            std::unique_lock<std::mutex> lock(_mutex);
            auto it = _bindings.find(ename);
            if (it == _bindings.end())
            {
                return false;
            }
            auto qit = it->second.find(qname);
            if(qit==it->second.end())
            {
                 return false; 
            }
            return true;
        }
        size_t size()
        {
            std::unique_lock<std::mutex> lock(_mutex);
            size_t total_size = 0;
            for(auto e:_bindings)
            {
                total_size+=e.second.size();
            }
            return total_size;
        }
        void clear()
        {
            std::unique_lock<std::mutex> lock(_mutex);
             _mapper.deleteTable();
            _bindings.clear();
        }

    private:
        std::mutex _mutex;
        BindingMapper _mapper;
        BindingMap _bindings;
    };
}
#endif